Another fog remedy may be to come ride with us in FL. Clear and warm last night
My experience was the opposite. I didn't like the Pro-Grip - the adhesive came undone allowing fog to occur between the Pro-Grip shield and the helmet shield. (And when it's between the two, you can't just wipe it off) The Fog City shields I've used have worked great.
Fog City had the clear adhesive and the Pro-Grip had the black rubber, right?
Yep. I liked the Pro-Grip at first, but after only a couple of months, the adhesive was starting to let go. My current Fog City has been on my shield since last season and is holding up well.
This looks Promising: http://www.webbikeworld.com/r4/ria-permanent-anti-fog-coating/